Structural member and method for manufacturing structural member

Abstract

A structural member includes a cylindrical main body member and at least one nonmagnetic bracket member which includes a cylindrical section and plate-shape sections protruding from the outer peripheral surface of the cylindrical section. The main body member is inserted into the cylindrical section of the bracket member, a gap is formed between the outer surface of the main body member and the inner surface of the cylindrical section in the root portion of a rib on the bracket member, and the entire circumference of the bracket member is electromagnetically contracted to fasten the structural member by swaging.

1 . A structural member comprising:
 a tubular main body member; and   at least one bracket member formed from a non-magnetic body, the bracket member including a tubular portion and a rib portion formed so as to protrude from the outer peripheral surface of the tubular portion,   wherein the main body member is inserted into the tubular portion of the bracket member, and the entire periphery of the bracket member is swaged to a reduced diameter by electromagnetic tube compression to be fastened onto the main body member so that a gap is formed between the inner surface of the tubular portion at a base portion of the rib portion of the bracket member and the outer surface of the main body member.   
     
     
         2 . The structural member according to  claim 1 , wherein a protrusion is formed in an area of the main body member that is in contact with the inner peripheral surface of the tubular portion at the base portion of the rib portion. 
     
     
         3 . The structural member according to  claim 1 , wherein the main body member is subjected to a bending process. 
     
     
         4 . The structural member according to  claim 1 , wherein at least part of the main body member is subjected to flattening process. 
     
     
         5 . The structural member according to  claim 1 , wherein the bracket member is made from an extruded material. 
     
     
         6 . A structural member comprising:
 frame members each formed from a non-magnetic body including a tubular portion and a rib portion formed so as to protrude from the outer peripheral surface of the tubular portion; and   a frame connecting member configured to connect the frame members to each other,   wherein at least part of the frame connecting member is inserted into the frame member, and the frame member and the frame connecting member are swaged to a reduced diameter and are fastened together by electromagnetic tube compression so that a gap is formed between the inner surface of the tubular portion at a base portion of the rib portion of the frame member and the outer surface of the frame connecting member.   
     
     
         7 . The structural member according to  claim 1 , wherein the non-magnetic body is made of an aluminum alloy. 
     
     
         8 . A method for manufacturing a structural member, comprising:
 inserting an inner member into a tubular member with a rib, the tubular member including a tubular portion and a rib portion that protrudes from the outer peripheral surface of the tubular portion;   disposing a magnetic field shaper so that the magnetic field shaper surrounds the tubular member with a rib, the magnetic field shaper having a cavity that extends along the outer periphery of the tubular member with a rib and concentrating magnetic fluxes generated by a coil conductor; and   swaging and fastening the tubular member with a rib onto the inner member using electromagnetic tube compression by passing an electrical current through the coil conductor.   
     
     
         9 . The method for manufacturing a structural member according to  claim 8 , wherein part of the magnetic field shaper is formed so as to protrude from a portion in which the coil conductor is wound around the outer periphery in the axial direction, and
 wherein the protruding part of the magnetic field shaper surrounds the tubular member with a rib.   
     
     
         10 . The method for manufacturing a structural member according to  claim 8 , wherein the tubular member with a rib is subjected to a softening process before the swaging and fastening the tubular member with a rib onto the inner member.